"Just for the record: ClamAV is one of the worst antivirus on Unix."
What is better? Are they GNU?
And yes there are Viruses out there for linux but like you said the desktop user doesn't need to worry about them as of today, who knows about next week. That's why I didn't start down that path. Actually this anti-virus issue is a touchy subject in linux forums. I suppose it's a case of your pairnioa level.
I just thought that like everything else in Mint that the Clam AV should do everything (i.e make the menu link and update the database)
Clam AV is a CL package, I think there is a GUI front end for it, but it's a seperate package.
It is most likely doing just that, updating the database. It's just you can't see it because of LinuxMint silent boot and shutdown. If you remove silent and splash from the boot line in grub next time you boot and watch, you most likely see Clam AV doing it's thing. It starts on boot, on shutdown it updates it's database before the system goes down.
You might see a lot of other things that tweek your interest. Such as an error here or there during boot, which you can't see because of that silent/splash.